The present disclosure relates to an image forming apparatus provided with an apparatus main body and an upper structure which can be set in a closing posture for covering the upper surface of the apparatus main body and an opening posture for exposing the upper surface.
There is known an image forming apparatus provided with an apparatus main body for housing an image forming unit for forming an image on a sheet and an auto document feeder (upper structure) mounted on the apparatus main body openably and closably relative to the upper surface of the apparatus main body. The auto document feeder includes a document placing portion on which a document is to be placed and a document discharging portion. When the auto document feeder is in a reading posture (closing posture), a document placed on the document placing portion is fed to a document reading surface and then discharged to the document discharging portion.
In the image forming apparatus of this type, if the auto document feeder is opened and closed while a document is discharged to the document discharging portion by the auto document feeder, the document may depart from a conveyance path and may not be able to be normally read. Further, the opening and closing operation may cause the document to fall or be jammed. Thus, a detector for detecting the posture of the auto document feeder (posture detector) is provided. A control unit for controlling a document conveying operation performs a control for prohibiting the use of the auto document feeder when it is detected by this detector that the auto document feeder is not closed during the conveyance of the document by the auto document feeder.
However, in the image forming apparatus as described above, a user may open the auto document feeder early, trying to manually place another document on the document reading surface for image reading before the last document is discharged after the last document is read. In such a case, the use of the auto document feeder is prohibited and the last document is not discharged although there is no problem in a subsequent image forming operation since the reading of the document is already finished. Thus, the reading of another document has to be waited until the prohibition of the use of the auto document feeder is lifted, which may cause the user to feel annoyed.
An object of the present disclosure is to provide an image forming apparatus capable of efficiently performing a document reading operation.